Weird file types on phone. Do I need them?

[AC Question]

Samsung Galaxy S5 running Android 5.0 Verizon

My internal 16 GB has about 1.2 GB free. When I connect to my laptop and examine files I have a lot of files with a really long file name like this one: "14f3bb926d6038b645c2e47f0ca4f83b53ad26793b4e436529a51b689baa67c.0"
Or
"DC8FsIdVi9Y.135.1432574970750153.1257.1448400829940.v1.exo"
or simply
"1425930443878" with no file type

What are these files and do I need them? Are they temp or cache that can be deleted.

 

[B. Diddy]

Welcome to Android Central! What directory are those files in?

 

[mbaumser]

"14f3bb926d6038b645c2e47f0ca4f83b53ad26793b4e436529a51b689baa67c.0" is in Rocketplayer > ArtThumnails So I guess that's self explanitory I have all my music on my external card but it looks like the app puts the art work on the phones card

"1425930443878" is in Phone > Android > Data> Com.android.providers.media > albumthumbs

I went to storage>cached data and cleared all and that got rid of the .exo and cleared about 4GB of space